The astrophysical S-factor of the direct 18O(p, γ)19F capture by the ANC method

We attempted to determine the astrophysical S-factor of the direct part of the 18 O(p, γ ) 19 F capture by the indirect method of asymptotic normalization coefficients (ANC). We measured the differential cross section of the transfer reaction 18 O( 3 He, d) 19 F at a 3 He energy of 24.6 MeV. The measurement was realized on the cyclotron of the NPI in Řež, Czech Republic, with the gas target consisting of the high purity 18 O (99.9 %). The reaction products were measured by eight ∆E-E telescopes composed from thin and thick silicon surface-barrier detectors. The parameters of the optical model for the input channel were deduced by means of the code ECIS and the analysis of transfer reactions to 12 levels of the 19 F nucleus up to 8.014 MeV was made by the code FRESCO. The deduced ANCs were then used to specify the direct contribution to the 18 O(p, γ ) 19 F capture process and were compared with the mutually different results of two works

26Mg target for nuclear astrophysics measurements

Two nuclear reactions of astrophysical interest, 26Mg(3He,d)27Al and 26Mg(d,p)27Mg, were measured for extraction of the Asymptotic Normalization Coefficients. Investigation of the target composition is presented, as well as the effects that showed up during analysis of the in-beam data obtained on CANAM accelerators in the Nuclear Physics Institute of the Czech Academy of Sciences (NPI CAS)

The astrophysical S-factor of the direct 18

We attempted to determine the astrophysical S-factor of the direct part of the 18O(p, γ)19F capture by the indirect method of asymptotic normalization coefficients (ANC). We measured the differential cross section of the transfer reaction 18O(3He, d)19F at a 3He energy of 24.6 MeV. The measurement was realized on the cyclotron of the NPI in Řež, Czech Republic, with the gas target consisting of the high purity 18O (99.9 %). The reaction products were measured by eight ∆E-E telescopes composed from thin and thick silicon surface-barrier detectors. The parameters of the optical model for the input channel were deduced by means of the code ECIS and the analysis of transfer reactions to 12 levels of the 19F nucleus up to 8.014 MeV was made by the code FRESCO. The deduced ANCs were then used to specify the direct contribution to the 18O(p, γ)19F capture process and were compared with the mutually different results of two works

Adaptive structure tensors and their applications

The structure tensor, also known as second moment matrix or Förstner interest operator, is a very popular tool in image processing. Its purpose is the estimation of orientation and the local analysis of structure in general. It is based on the integration of data from a local neighborhood. Normally, this neighborhood is defined by a Gaussian window function and the structure tensor is computed by the weighted sum within this window. Some recently proposed methods, however, adapt the computation of the structure tensor to the image data. There are several ways how to do that. This article wants to give an overview of the different approaches, whereas the focus lies on the methods based on robust statistics and nonlinear diffusion. Furthermore, the dataadaptive structure tensors are evaluated in some applications. Here the main focus lies on optic flow estimation, but also texture analysis and corner detection are considered

Diversidad bacteriana ruminal en cabras criollas alimentadas con una dieta tradicional

Los rumiantes poseen una gran eficiencia en la utilización de los sustratos presentes en las células vegetales, dada la presencia de bacterias anaeróbicas y enzimas hidrolíticas en el rumen. Debido a las limitaciones del cultivo anaeróbico, se han desarrollado nuevas técnicas de biología molecular que han permitido el análisis de tales microorganismos, sin la necesidad de cultivarlos, mediante la secuenciación de genes específicos. Nuestro equipo de investigación logró aislar y caracterizar a la especie bacteriana Pseudobutyrivibrio xylanivorans, a partir del rumen de cabras Criollas, proponiendo el uso de esta cepa como probiótico. Es necesario conocer la diversidad de las bacterias ruminales de cabras sometidas a diversas condiciones nutricionales, ya que de esta manera se puede prever la intensidad de los cambios generados por la introducción de la bacteria probiótica

Mutational Patterns in RNA Secondary Structure Evolution Examined in Three RNA Families

The goal of this work was to study mutational patterns in the evolution of RNA secondary structure. We analyzed bacterial tmRNA, RNaseP and eukaryotic telomerase RNA secondary structures, mapping structural variability onto phylogenetic trees constructed primarily from rRNA sequences. We found that secondary structures evolve both by whole stem insertion/deletion, and by mutations that create or disrupt stem base pairing. We analyzed the evolution of stem lengths and constructed substitution matrices describing the changes responsible for the variation in the RNA stem length. In addition, we used principal component analysis of the stem length data to determine the most variable stems in different families of RNA. This data provides new insights into the evolution of RNA secondary structures and patterns of variation in the lengths of double helical regions of RNA molecules. Our findings will facilitate design of improved mutational models for RNA structure evolution

Mainstreams of Horizontal Gene Exchange in Enterobacteria: Consideration of the Outbreak of Enterohemorrhagic E. coli O104:H4 in Germany in 2011

Escherichia coli O104:H4 caused a severe outbreak in Europe in 2011. The strain TY-2482 sequenced from this outbreak allowed the discovery of its closest relatives but failed to resolve ways in which it originated and evolved. On account of the previous statement, may we expect similar upcoming outbreaks to occur recurrently or spontaneously in the future? The inability to answer these questions shows limitations of the current comparative and evolutionary genomics methods.status: publishe